scholarly journals Stargardt Disease Caused by a Rare Combination of Double Homozygous Mutations

Medicina ◽  
2013 ◽  
Vol 49 (8) ◽  
pp. 60
Author(s):  
Danielius Serapinas ◽  
Viltautė Obrikytė ◽  
Raimundas Sakalauskas
Keyword(s):  
Autosomal Recessive ◽  
Severe Disease ◽  
Disease Phenotype ◽  
Stargardt Disease ◽  
Recessive Mutations ◽  
Rare Combination ◽  
Abca4 Gene ◽  
Genetic Mechanisms ◽  
Blurry Vision ◽  
Autosomal Recessive Pattern

Stargardt disease is a juvenile macular degeneration most often inherited in an autosomal recessive pattern, characterized by decreased vision in the first 2 decades of life. This report presents a clinical case of Stargardt disease: a 10-year-old female patient complained of blurry vision, and in a 4-year period, her visual acuity was reduced from OD=0.3 and OS=0.3 to OD=0.08 and OS=0.1, respectively. A genetic analysis revealed a rare combination of 2 homozygous recessive mutations in the ABCA4 gene, which caused Stargardt disease. The presence of different genetic mechanisms leading to a severe disease phenotype can challenge molecular geneticists, ophthalmologists, and genetic counselors.

scholarly journals An ABCA4 loss-of-function mutation causes a canine form of Stargardt disease

2018 ◽  
Author(s):  
Suvi Mäkeläinen ◽  
Marta Gòdia ◽  
Minas Hellsand ◽  
Agnese Viluma ◽  
Daniela Hahn ◽  
...  
Keyword(s):  
Visual Impairment ◽  
Retinal Degeneration ◽  
Autosomal Recessive ◽  
Retinal Pigment ◽  
Clinical Signs ◽  
Premature Stop Codon ◽  
Large Animal ◽  
Loss Of Function ◽  
Stargardt Disease ◽  
Abca4 Gene

Autosomal recessive retinal degenerative diseases cause visual impairment and blindness in humans and dogs. Currently, no standard treatment is available but pioneering gene therapy-based canine models have been instrumental for clinical trials in humans. To study a novel form of retinal degeneration in Labrador retriever dogs with clinical signs indicating cone and rod degeneration, we used whole-genome sequencing of an affected sib-pair and their unaffected parents. A frameshift insertion in the ATP binding cassette subfamily A member 4 (ABCA4) gene (c.4176insC), leading to a premature stop codon in exon 28 (p.F1393Lfs1395) was identified. In contrast to unaffected dogs, no full-length ABCA4 protein was detected in the retina of an affected dog. The ABCA4 gene encodes a membrane transporter protein localized in the outer segments of rod and cone photoreceptors. In humans, the ABCA4 gene is associated with Stargardt disease (STGD), an autosomal recessive retinal degeneration leading to central visual impairment. A hallmark of STGD is the accumulation of lipofuscin deposits in the retinal pigment epithelium. The discovery of a canine homozygous ABCA4 loss-of-function mutation may advance the development of dog as a large animal model for human STGD.

ABCA4-Associated Stargardt Disease

2020 ◽  
Vol 237 (03) ◽  
pp. 267-274 ◽  
Author(s):  
Mubeen Khan ◽  
Frans P.M. Cremers
Keyword(s):  
Autosomal Recessive ◽  
Late Onset ◽  
Human Kidney ◽  
In Vitro Assays ◽  
Kidney Cells ◽  
Stargardt Disease ◽  
Abca4 Gene ◽  
Transcriptomics Data ◽  
Degree Of Severity

AbstractAutosomal recessive Stargardt disease (STGD1) is associated with variants in the ABCA4 gene. The phenotypes range from early-onset STGD1, that clinically resembles severe cone-rod dystrophy, to intermediate STGD1 and late-onset STGD1. These different phenotypes can be correlated with different combinations of ABCA4 variants which can be classified according to their degree of severity. A significant fraction of STGD1 cases, particularly late-onset STGD1 cases, were shown to carry only a single ABCA4 variant. A frequent coding variant (p.Asn1868Ile) was recently identified which – in combination with a severe ABCA4 variant – is generally associated with late-onset STGD1. In addition, an increasing number of rare deep-intronic variants have been found and some of these are also associated with late-onset STGD1. The effect of these and other variants on ABCA4 RNA was tested using in vitro assays in human kidney cells using specially designed midigenes. With stem cells and photoreceptor progenitor cells derived from patient skin or blood cells, retina-specific splice defects can be assessed. With expert clinical examination to distinguish STGD1 cases from other maculopathies, as well as in-depth genomics and transcriptomics data, it is now possible to identify both mutant ABCA4 alleles in > 95% of cases.

scholarly journals Antisense Oligonucleotide Screening to Optimize the Rescue of the Splicing Defect Caused by the Recurrent Deep-Intronic ABCA4 Variant c.4539+2001G>A in Stargardt Disease

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 452 ◽  
Author(s):  
Alejandro Garanto ◽  
Lonneke Duijkers ◽  
Tomasz Z. Tomkiewicz ◽  
Rob W. J. Collin
Keyword(s):  
Pluripotent Stem Cells ◽  
Antisense Oligonucleotides ◽  
Autosomal Recessive ◽  
Stargardt Disease ◽  
Single Nucleotide ◽  
Significant Correction ◽  
Nucleotide Mismatch ◽  
Single Nucleotide Mismatch ◽  
Splicing Defects ◽  
Induced Pluripotent

Deep-sequencing of the ABCA4 locus has revealed that ~10% of autosomal recessive Stargardt disease (STGD1) cases are caused by deep-intronic mutations. One of the most recurrent deep-intronic variants in the Belgian and Dutch STGD1 population is the c.4539+2001G>A mutation. This variant introduces a 345-nt pseudoexon to the ABCA4 mRNA transcript in a retina-specific manner. Antisense oligonucleotides (AONs) are short sequences of RNA that can modulate splicing. In this work, we designed 26 different AONs to perform a thorough screening to identify the most effective AONs to correct splicing defects associated with c.4539+2001G>A. All AONs were tested in patient-derived induced pluripotent stem cells (iPSCs) that were differentiated to photoreceptor precursor cells (PPCs). AON efficacy was assessed through RNA analysis and was based on correction efficacy, and AONs were grouped and their properties assessed. We (a) identified nine AONs with significant correction efficacies (>50%), (b) confirmed that a single nucleotide mismatch was sufficient to significantly decrease AON efficacy, and (c) found potential correlations between efficacy and some of the parameters analyzed. Overall, our results show that AON-based splicing modulation holds great potential for treating Stargardt disease caused by splicing defects in ABCA4.

Novel mutation in ferroportin1 is associated with autosomal dominant hemochromatosis

Blood ◽  
2002 ◽  
Vol 100 (2) ◽  
pp. 692-694 ◽  
Author(s):  
Daniel F. Wallace ◽  
Palle Pedersen ◽  
Jeannette L. Dixon ◽  
Peter Stephenson ◽  
Jeffrey W. Searle ◽  
...  
Keyword(s):  
Iron Transport ◽  
Autosomal Recessive ◽  
Iron Homeostasis ◽  
Autosomal Dominant ◽  
Novel Mutation ◽  
Hfe Gene ◽  
Excess Iron ◽  
Chromosome 1Q ◽  
Australian Family ◽  
Autosomal Recessive Pattern

Abstract Hemochromatosis is a common disorder characterized by excess iron absorption and accumulation of iron in tissues. Usually hemochromatosis is inherited in an autosomal recessive pattern and is caused by mutations in the HFE gene. Less common non-HFE–related forms of hemochromatosis have been reported and are caused by mutations in the transferrin receptor 2 gene and in a gene localized to chromosome 1q. Autosomal dominant forms of hemochromatosis have also been described. Recently, 2 mutations in theferroportin1 gene, which encodes the iron transport protein ferroportin1, have been implicated in families with autosomal dominant hemochromatosis from the Netherlands and Italy. We report the finding of a novel mutation (V162del) in ferroportin1 in an Australian family with autosomal dominant hemochromatosis. We propose that this mutation disrupts the function of the ferroportin1 protein, leading to impaired iron homeostasis and iron overload.

scholarly journals Clinical and molecular genetic study of 12 Italian families with autosomal recessive Stargardt disease

2012 ◽  
Vol 11 (4) ◽  
pp. 4342-4350 ◽  
Author(s):  
M. Oldani ◽  
S. Marchi ◽  
A. Giani ◽  
S. Cecchin ◽  
E. Rigoni ◽  
...  
Keyword(s):  
Genetic Study ◽  
Autosomal Recessive ◽  
Molecular Genetic ◽  
Stargardt Disease ◽  
Molecular Genetic Study

scholarly journals Relieving treatment of bronchial asthma attack in schoolchildren suffer from severe disease phenotype

2017 ◽  
Vol 0 (6 (14)) ◽  
pp. 4-7
Author(s):  
Mykola Garas ◽  
Gennadіy Lekhkun ◽  
Vladislav Lysenko ◽  
Basiuk Natalia
Keyword(s):  
Bronchial Asthma ◽  
Severe Disease ◽  
Disease Phenotype ◽  
Asthma Attack

scholarly journals AN AYURVEDIC MANAGEMENT OF SPINAL MUSCULAR ATROPHY (SMA) – A CASE STUDY

2021 ◽  
Vol 9 (11) ◽  
pp. 2897-2902
Author(s):  
Raheena B ◽  
Shaila Borannavar ◽  
Ananta S Desai
Keyword(s):  
Spinal Muscular Atrophy ◽  
Motor Neurons ◽  
Autosomal Recessive ◽  
Muscular Atrophy ◽  
Genetic Disorder ◽  
The Body ◽  
Erect Posture ◽  
Smn1 Gene ◽  
Autosomal Recessive Pattern

Spinal Muscular Atrophy (SMA) is the second leading genetic disorder inherited in the autosomal recessive pattern due to the absence of the SMN1 gene characterized by loss of motor neurons and progressive muscle wasting, often leading to dependent life and decreased life span. In Ayurveda, this condition can be considered as Kulaja Vyadhi wherein the patient’s Mamsa and Snayu is affected by Vata. This can be regarded as Mamsa-Snayugata Sarvanga Vata. It is said that Prakruta Vata dosha is the life, it is the strength, it is the sustainer of the body, it holds the body and life together. If it is Vikruta it produces Sankocha, Khanja, Kubjatva, Pangutva, Khalli and Soshana of Anga. So, in this disease aggravated Vata does the vitiation of Mamsa and Snayu thus leading to Soshana of both, resulting in Stambha, Nischalikarana of Avayava. A 21years female patient was admitted to our I.P.D with c/o of reduced strength in all four limbs leading to the inability to walk and to maintain erect posture during standing and sitting positions. Based on Ayurvedic principles the patient was initially subjected to Avaranahara Chikitsa followed by Brimhana line of management. Keywords: Mamsagata vata, Snayugata vata, Sarvanga vata, Spinal muscular atrophy (SMA)

THE GENETICS OF THANATOPHORIC DWARFISM

PEDIATRICS ◽  
1973 ◽  
Vol 51 (1) ◽  
pp. 104-109
Author(s):  
Sergio Danilo Junho Pena ◽  
Harold O. Goodman
Keyword(s):  
Autosomal Recessive ◽  
Autosomal Recessive Inheritance ◽  
Recurrence Risk ◽  
Recessive Inheritance ◽  
Review Of The Literature ◽  
Marked Contrast ◽  
Thanatophoric Dwarfism ◽  
Genetic Mechanisms ◽  
Sporadic Cases

Two cases of thanatophoric dwarfism are presented with guidelines for diagnosis. A review of the literature is made, and from that, a discussion of possible genetic mechanisms is made. Although data favor a polygenic mechanism at the present time, it is possible that some cases are due to autosomal recessive inheritance. An empiric recurrence risk of 1:50 is suggested by cases published to date. This is in marked contrast to the small recurrence risk for sporadic cases of classical achondroplasia and the importance of differentiation between these two entities cannot be overemphasized.

scholarly journals Molecular Analysis of the ABCA4 Gene Mutations in Patients with Stargardt Disease Using Human Hair Follicles

2020 ◽  
Vol 21 (10) ◽  
pp. 3430
Author(s):  
Aneta Ścieżyńska ◽  
Marta Soszyńska ◽  
Michał Komorowski ◽  
Anna Podgórska ◽  
Natalia Krześniak ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Splice Site ◽  
Human Hair ◽  
Gene Mutations ◽  
Hair Follicles ◽  
Cdna Sequencing ◽  
Stargardt Disease ◽  
Protein Levels ◽  
Abca4 Gene ◽  
Functional Consequences

ABCA4 gene mutations are the cause of a spectrum of ABCA4 retinopathies, and the most common juvenile macular degeneration is called Stargardt disease. ABCA4 has previously been observed almost exclusively in the retina. Therefore, studying the functional consequences of ABCA4 variants has required advanced molecular analysis techniques. The aim of the present study was to evaluate whether human hair follicles may be used for molecular analysis of the ABCA4 gene splice-site variants in patients with ABCA4 retinopathies. We assessed ABCA4 expression in hair follicles and skin at mRNA and protein levels by means of real-time PCR and Western blot analyses, respectively. We performed cDNA sequencing to reveal the presence of full-length ABCA4 transcripts and analyzed ABCA4 transcripts from three patients with Stargardt disease carrying different splice-site ABCA4 variants: c.5312+1G>A, c.5312+2T>G and c.5836-3C>A. cDNA analysis revealed that c.5312+1G>A, c.5312+2T>G variants led to the skipping of exon 37, and the c.5836-3C>A variant resulted in the insertion of 30 nucleotides into the transcript. Our results strongly argue for the use of hair follicles as a model for the molecular analysis of the pathogenicity of ABCA4 variants in patients with ABCA4 retinopathies.

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